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TO ALL WHOM IT MAY CONOERN:

Be it known that l, F. W. DAvIDsON, of Cleveland, in the county of Cuyahoga, and State of Ohio, have invented certain nev.7 and useful improvements in Steam Valves; and I do hereby declare that the following is a full and complete description of the same, reference being had to the accompanying drawings, making a part of this specitication, in whichy Figure 1 is an end View of the valve and chamber.

Figure 2, a 'vertical longitudinal section.

Figure 3, a vertical transverse section.

Figures 4 and 5, a view of detached valves.

Like letters of reference refer to like parts in the several views` A, tig. l, is a section of a-st-eam cylinder upon which are placed and secured the valve-chambers D G, and in which are placedv and operate the valves D E, figs. .2 and 3. Of these valves, D is the main valve, and E the governor valve,`and which are constructed alike, as shown in figs. `vl and 5, in which it will be seen that they are cylindrical, with a longitudinal opening, F, through the centre. G, the faces ofthe valves, are on eachside of the opening, and the side G', between the two, are-lutcd, so that when the valves are in the chambers the lluted section of the valve and side of the chambers together make asuh-chamber, H, as shown in tig. 3, to which reference will hereafter be made. l is a pivot by which the rear end of the valve is supported; J, aA short shaft supporting the front endof the same, and which is projected through the head ofthe chamber, and to which are keyed the crank and pin K and K, by which the valves are operated. l L, tig. 2, is the induction opening` leading the steam from the steam pipe into the cylinder', first passing through side channels M and valves down the throat N into the chamber D, from which, into the cylinder A through the throats 0 0.

Having thus indicated the several parts of the apparatus, the practical operation ofthe same as followsr The valve E is connected to the governor by the cra-nl". and pin referred to,.and by which itis made to oscillatc, thus opening and closing the valve, more or less, as the case maybe. The position of the valve as shovvn in the drawing is lsuch as to' open. the ports e Zi, and through which the steam passes to the valve below. The `two ports being of equal capacity, the steam passes Ywith equal volume through cach, but in order to pass through the port b, it must first pass through the valve, and partially so in order to pass the port a. Thus it will be seen that the steam fills the space F in the Avalve at all times, land exerts an equal pressure on each side; thus the valve sequallyand truly balanced by the equal pressure of the steam while passing through it into the chamber D. The valve D is connected to the eccentric and made to oscillate thereby. The position of this valve is such Aas to partially close the two ports ed. It Will be evident that-in order for the steam to enter the port d, it must first pass down through the valve, as in the fermer case, and thus the pressure yof the steam is exerted equally on each side of the valve, and is therefore equally balanced; As the valve is'moved to the right, the port d is opened and the steam enters the cylinder through the channel O; at the same time the port c is opening and the inducted steam ret-urns through that port into the sub-chamber H, througlrthe port H into the induction chamber l?, and exhausts into the pipe Q, hg. 2, and so cn to the reverse action of the valve. The steam enters the port c, thence along the channel O into the cylinder. At tlie same time the inducted steam returns through the port (l, through the port H, into the @duct-ion chamber P, and exhausts into the pipe Q as before. Thus the steam is made to pass directly through the valve to the cylinder and exhaust at the sides through the sub-chambers referred to. 'lhc valve by this means is at all times filled with steam, it forming a section of the channel through which the steam must pass to the cylinder, and whatever 'the' pressure of the steam may bc, it is equally exerted upon both sides of thc valve, and which is therefore equally balanced in its oscillation.

The advantages resulting from a valve constructed as above described, ure viz: Acting as a main valve its operation is attended by a large reduction in the amount of friction under'the samc'pressure of steam, hence the valve will Wear longer, and therefore will not require facing so often.. By exhausting the'steam at the sides of the cylinder it finds a more direct and immediate passage to-theair. Acting as a governorvalveit. offer but little obstruction to thesteam in its passagc to the cylinder. The valve can bemade smaller in'dian eter than an ordinary valve, and therefore will require less material and room, and, While operating as a throttle,

is at the same time a. balanced valve, tight anr'l always reliable. As this valve i it is therefore more easily and cheaply fitted to the chamber than the ordinary' of view' itis much cheaper than any other valve in Lise,

s constructed slightly tapering, valve. In an economical point and by its reducing 'largely the 'rieton, of the engine o proportionate amount of power is gained, hence the engine can be run at a. much less expense. M

What I claim as my improvement, and desire to secure by Letters Potent, is- The arrangement of the .valves D and E with reference to eaoh other, and the arrangement of tlie ingress l and egress Steam passages upon the principle and in the manner as herein set forth.

' F. W. DAVIDSON. Witnesses:

J. H. BURRIDGE, FRANK ALDEN. l 

